Once you have received the Transfer Confirmation Email from OpenSrS Tucows, simply click  on the link found in the message and you will be taken to the following page:

In the "Domain" field you must type in the name of the domain that needs to be transferred.
In the "Transfer-Key" field you must type in the code found in the email sent by Tucows.

After clicking the Retrieve Transfer Request button, you will be taken to the following page which shows the name of the domain, the name of the current registrar, a link to the Whois.

You must then check the check box found next to the sentence 'to indicate that the Registrant(s) for the domain listed above':

Type in the Authorization Code given to you by your current provider. To confirm the request then click on Submit Request: